Direct image composing machine having means to prevent pressure overload of printing characters

ABSTRACT

A direct image printing machine is provided especially adapted for composing a line of print on paper tape. The machine prints images from raised characters and coated transfer paper, such as carbon coated paper, onto a printable paper strip when these elements are stacked together and commonly compressed between a linearly closing anvil and piston. The machine may be used with a wide range of type style and sizes of raised characters. A control system regulates the force of the thrust during the printing process to guard against pressure overload on characters of a particular type or size. One of a series of flat platens of differing thicknesses is selectively used between the anvil and piston to control interference, the thickness of a selected platen member being correlated with the surface image area of a selected raised character during a printing operation is maintained below a predetermined maximum. Additionally, the printing machine is designed to accept only a master or printing disc having raised characters of an area to be used with a selected platen member and to reject other printing discs. The printing disc preferably is formed from a deformable, resilient, elastic, synthetic polymeric resin having raised characters of different areas.

United States Patent [1 1 Lewis [11] 3,768,619 [451 Oct. 30, 1973 DIRECT IMAGE COMPOSING MACHINE HAVING MEANS TO PREVENT PRESSURE OVERLOAD OF PRINTING CHARACTERS [75] Inventor: Richard A. Lewis, Wickliffe, Ohio [73] Assignee: Adressograph-Multigraph Corporation, Cleveland, Ohio [22] Filed: Dec. 29, 1971 [21] Appl. No.: 213,273

[52] U.S. Cl l97/6.4, lO1/401.1, 101/18 [51] Int. Cl B41] l/22 [58] Field of Search 197/6.4, 6.5, 6.6, 197/6.2, 6.7; 101/398, 18

[56] References Cited UNITED STATES PATENTS 2,589,682 3/1952 Dudis 101/398 X 2,951,571 9/1960 Colyer et al. 197/6.7

3,198,168 8/1965 Grupe 197/6.6 X 3,215,245 11/1965 Thiene et a1.... 197/149 X 3,308,749 3/1967 Dowd' 101/368 X 3,389,772 6/1968 Sjogren et a1... 101/288 X 3,428,158 2/1969 Brown 197/6.6

Primary ExaminerEdgar S. Burr Attorney-Russell L. Root et al.

[5 7] ABSTRACT A direct image printing machine is provided especially adapted for composing a line of print on paper tape. The machine prints images from raised characters and coated transfer paper, such as carbon coated paper, onto a printable paper strip when these elements are stacked together and commonly compressed between a linearly closing anvil and piston. The machine may be used with a wide range of type style and sizes of raised characters. A control system regulates the force of the thrust during the printing process to guard against pressure overload on characters of a particular type or size. One of a series of flat platens of difiering thicknesses is selectively used between the anvil and piston to control interference, the thickness of a selected platen member being correlated with the surface image area of a selected raised character during a printing operation is maintained below a prcdeter mined maximum. Additionally, the printing machine is designed to accept only a master or printing disc having raised characters of an area to be used with a selected platen member and to reject other printing discs. The printing disc preferably is formed from a deformable, resilient, elastic, synthetic polymeric resin having raised characters of different areas.

10 Claims, 7 Drawing Figures PATENIEnnmo ma 3.768.619 SHEET 1 [If 4 INVENTOR. RICHARD A. LEWIS ATTORNEY PATENIEDnmaoms 3.768.619

SHEET 20F 4 INVENTOR. RICHARD A. LEWIS {g g} P ATTORNEY PAIENIEflnmo I975 3.768.619 sum 3 OF 4 ||I||||||||lllIlllIllllllllllllllllllli INVENTOR. RICHARD A. LEWIS lax/W802 ATTORNEY DIRECT IMAGE COMPOSING MACHINE HAVING MEANS TO PREVENT PRESSURE OVERLOAD OF PRINTING CHARACTERS BACKGROUND OF THE INVENTION Composing machines are known in the art for producing intelligence in strip form, usually in relatively large letters. Headlines, section headings, etc., are prepared in this manner and then arranged, for example, on a make-up page for magazine advertising or the like. After completion, the page is photographed and a lithographic master conventionally prepared from the exposure as for use on an offset printing press. Composing machines of this general type are described in U.S. Pat. No. 2,742,830 to Wirtz and U.S. Pat. No. 3,440,936 to Tibbling et al. and are also sold by the Addressograph- Multigraph Corporation under the trademarks VARI- TYPE and HEADLINER machines.

These machines are of the photocomposing type in which each letter on a strip is individually exposed and photographically developed. While such machines have been and are commercially successful, for certain applications it is desired to avoid the photoreproductive technique and employ a direct image, letterpress transfer of the character in superimposed relation with a coated transfer paper and a printable sheet is placed between a cooperating hammer and anvil which, upon closing, effect a print of the character from the transfer sheet onto the printable sheet.

A direct image composing machine has certain advantages as compared to a photocomposing machine in that processing of the tape is eliminated, and errors are reduced by providing visual access of the image area which can be continuously monitored as the line of print is being formed. Alterations and corrections can be made immediately without delay for line completion or processing. Color images are also possible as from transfer paper coated with color pigmented material.

However, there previously have been certain disadvantages as well to a direct image composing machine. Platen misalignment and varying and unknown pressure loads contribute to inconsistent results. Roller platens, that is, those which roll over a raised character when stacked with transfer paper, etc., present overlap problems between characters and also a varying load on a series of different characters. With roller platens there is also a different reaction of the roller to edges than to flat surfaces, and relative movement of the stacked materials is apt to occur.

A primary difficulty with direct image transfer of characters is that from a constant pressure source the actual transfer pressure exerted upon a particular character varies, depending on the total printing area afforded by the character and/or thickness or height by which it is raised. Thus, for example, a period has extremely small printable area as compared to a capital W. At the same time, the transfer pressure must at a minimum be sufficiently great to effect a full, solid impression of those characters offering the most resistance to a pressure transfer. Accordingly, characters of smaller printing areas, and especially those combined with greatest raised height, are often overloaded with pressure per unit of printing area. As a result, such characters are rapidly worn in use causing ragged and smeared prints. Or they may become crushed beyond use. This problem is particularly augmented in a direct image transfer of characters when different master or printing discs are to be used in the same machine, and the discs vary significantly as to the style, font, or size of raised characters. For example, one printing disc may have a relatively large bold font, while another may have a relatively small and delicate script font. The pressure needed for such two different discs varies substantially. Yet, when a relatively great pressure is applied to the relatively large bold font, there are still relatively tiny area characters of that font, such as a period, which requires less pressure than a large capital letter of the more delicate script font.

SUMMARY OF THE INVENTION In the present invention, these problems are overcome by the preferred use of a'master printing disc formed of a deformable, resilient, elastic, synthetic polymeric resin, and by use of a printing machine having a series of platen members differing in thicknesses that are used with different master discs. An important characteristic of the deformable resinous nature of a master disc of the present invention is that at least the characters of the disc have elastic limits. The present invention contemplates the preparation of such resinous printing discs in which the relatively small raised characters are reduced in height to less than the height of the relatively large characters. This is accomplished by subjecting a resinous disc to a compressive force which exceeds the elastic limit of the relatively small characters because of their size, and thereby imparts a permanent set and reduction of the height of such characters, but which is insufficient to exceed the elastic limit of the relatively large characters which are left substantially unchanged.

The present direct image printing machine prints images from raised characters on printable paper from coated transfer ribbon or tape by means of a piston of substantially constant stroke which reciprocably and linearly moves a flat platen toward and away from a cooperating anvil. A positive but variable amount of interference is provided between the anvil and piston at their closest position of relative linear travel which is correlated with the style and size of the character to be printed. This regulates the amount of pressure of squeeze actually exerted on a character.

In addition, the present machine accepts in an operable position only a printing disc having raised characters of a type which may be effectively and safely used with the amount of interference then established between the piston and anvil. This enables the machine to be used with a wide range of different type and sizes of raised characters in which all are synchronized to inhibit overloads of pressure on the character style and size of characters being used by the machine.

In one form, the present machine for variably sized, raised characters includes a relatively stationary anvil and a piston having raised characters is mounted in an operable position in the machine for sequentially inserting raised characters between the piston and anvil where a selected character is stacked in superposed relation with a coated transfer sheet and a printable sheet. When the piston approaches the anvil, the assembly is compressed, and a print of the raised character is made from the transfer sheet onto the printable sheet.

In the preferred embodiment, a platen table rotatably mounted on the piston carries a series of platen members of differing thicknesses. An actuating turret has a drive connection with the platen table and rotates the latter to place a selected platen member in alignment between the piston and anvil and thereby provide a controlled interference therebetween. The actuating turret may have selective engaging means adapted to accept a master or printing disc in its operable position in the machine, only if the printing disc has raised characters of a height and printing area to be safely and effectively used with the selected platen member then in position between the piston and anvil. I

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric, exterior view of a composing machine of the present invention;

FIG. 2 is an isometric view of the composing machine of FIG. 1 from which the outer casing has been removed and parts are broken away for purposes of illustration;

FIG. 3 is a fragmentary, enlarged side view of the cooperating anvil and piston and illustrates the mounting of different platen members on the platen;

FIG. 4 is a fragmentary, isometric, partially schematic view of a platen table, turret, and printing disc and shows their manner of assembly;

FIG. 5 is a fragmentary, isometric, partially schematic view similar to FIG. 4 with the printing disc removed to illustrate the selective spindle operation of the turret; and

FIGS. 6 and 7 are fragmentary, diagrammatic views of an anvil and piston of the present printing machine at their closest position relative to each other and shows how the size and/or shape of a character can affect the amount of stress imparted on the character per unit area.

DESCRIPTION OF THE PREFERRED EMBODIMENT Structure The illustrated embodiment includes a general housing 10 having stepped tiers 11 and 12 (FIG. 1). An anvil 13 having a covering 14 rises from the rear of the housing 10 and extends forwardly over a circumferential area of a printing disc 15 mounted in an operable position on tier 11. The lower tier 12 has pushbuttons generally indicated at 16 for actuating the machine as by energizing and deenergizing circuits for operating electrical components of the printing machine, as well as dials, generally represented at 17, for adjusting spacing and/or feeding of the transfer and printable tapes as hereinafter mentioned. Such features are not part of the present invention and therefore are not described in detail.

Referring principally to FIGS. 2 through 7, the present printing machine includes a frame generally indicated at 19 (FIG. 2) having an E configuration which supports an anvil, a reciprocating piston, and their attendant operational parts. An upper leg 20 of E-shaped frame 19 has a vertically disposed opening to carry a hardened, metal cylinder 13 defining the anvil. The anvil cylinder extends through leg 20 and may be permanently installed or adjustably mounted for vertical movement, as viewed in FIGS. 2 and 3, as by a threaded, connection between the opening in leg 20 and cylinder 13 with lock nuts 21 to hold the anvil in position.

Middle leg 22 of E-frame 19 has a vertically disposed, relatively large piston opening 23 to accommodate freely the reciprocable linear movement of a piston 24.

A laterally extending ledge 25 fixed to the'top of the piston (FIG. 3) provides an off-center mounting for a rotatable platen table 26, such that piston 24 is always led in its movement toward the anvil 13 by a selected platen member when the piston is placed below a raised character ofa printing disc 15, as shown in FIGS. 2 and 3.

Platen table 26 is mounted for rotation about a vertical axis by means of a stub shaft 27. Shaft 27 has a shoulder 28 forming a radially enlarged end which screws into an internally threaded opening 30 in ledge 25. Platen table 26 seats on shoulder 28 and has an oversized opening to receive shaft 27 freely and rotate thereabout. The circumferential edge of platen table 26 has a series of evenly spaced teeth 31 (FIG. 5) to provide a non-slip turning of the table as hereinafter more fully described.

A series of platen strips 32, 33, 34, 35 and 36 are random spaced along the periphery of table 26. Each strip is of a different thickness and fixed to the platen table 26 by any suitable means such as cementing. Although five platen strips are illustrated, more or less strips may be used. The platen strips may be smooth, polished steel, but improved results are obtained with strips of a deformable, elastic, synthetic polymeric resin. Deformable strips yield slightly under pressure to provide some release to stress application. This, in turn, prolongs the useful life of a raised printing character while not detracting from the evenness and sharpness of a printed image. The resins act as a smooth transfer surface and as a spring to absorb impact energy as from the piston. Such polymeric resins may include polyvinyl chloride, the polyacrylic esters, polyethylene, polypropylene, polyurethane, and the like with suitable use of known plasticizers if necessary to provide desired strength and fatigue characteristics. A preferred resin is one purchased from DuPont under trademark Delrin. If desired, a resilient, elastic strip may also be secured under the anvil 13.

The platen table 26 may be fabricated from metal or from a polymeric resin. A resinous table is preferred since it rides well around shaft 27, which is usually metal, with little wear. Resins from which the platen table may be made include those previously mentioned as well as others, such as ureaformaldehyde, melamineformaldehyde, epoxy, and polyester resins. It is preferable to make table 26 and platen strips 32 through 36 from the same polymeric resin.

Drive means linearly reciprocates piston 24 through a substantially constant stroke of travel. In the illustrated embodiment, the drive means includes a stan-' dard electric motor 37 which by pulleys 38 and 39 and interconnecting drive belt 40 rotates a shaft 42 conventionally journaled for rotation in a gear box 43 and having a worm gear 44 at right angles to shaft 42 and carries a cam wheel 47 and spur gear 48 which engages the worm gear 44. The driven rotation of shaft 46 is clutched when desired by conventional means, such as by a standard clutch mechanism generally indicated at 50, to a connecting rod 51 pivotally journaled eccentrically to the end of the clutch mechanism. The linear reciprocationof connecting rod 51 operates a toggle having links 52 and 53 (FIG. 3) which are commonly and pivotally joined to the end of rod 51 by pin 54. Leg 55 of E -frame 19 has a cutout portion 56 in which link 52 is pinned for reversible pivoting. Link 53 has a clevis 57 pivotally joined to a lug 58 depending from piston 24.

Gear box 43 also supports positioning means for turning the platen table 26 and preferably also carries the printing disc 15. The positioning means includes in the embodiment illustrated selective engaging means which permits a printing disc to be mounted with respect to the printing machine, only if that printing disc has raised characters of a height and/or printing area to be used with the platen strip selected on platen table 26. More particularly, the positioning means includes a turret 60 mounted for free rotation about a metal stub shaft 61 fixed relatively to the top of the gear box 43. Turret 60 may be plastic like platen table 26 and turret 60 and shaft 61 may be mounted with respect to each other in the manner illustrated in FIG. 3 for platen table 26 and shaft 27. As in table 26, the circumferential edge of turret 60 has a series of teeth 62. Table 26 and turret 60 have substantially the same diameter and are joined by a continuous connecting belt 63 having teeth 64 to mate with teeth 31 and 62 of the table and turret, respectively. Turret 60 cannot be turned, therefore, without turning table 26 through the same angle.

Turret 60 has a series of five vertically disposed openings in which five spindles indicated at 32a, 33a, 34a, 35a and 36a are free to move axially. The spindles occupy the same positions on turret 60 with respect to its center, as the platen strips 32 through 36 do on platen table 26 with respect to its center. Each spindle represents a platen strip and is used to correlate a proper printing disc like printing disc with the platen strip then in operable position between the anvil l3 and piston 24.

The upper end of each spindle has indicia to indicate which of the series of platen strips is positioned at any given time between the anvil l3 and piston 24. Further, such indicia may be designed to receive only a printing disc having raised characters of a height and/or printing area to be used with a particular, selected platen strip. Thus, spindle 32a has an exposed upper end in geometric shape selected so that they are not interchangeable. Therefore, the shape will assure correct platen selection. A cam thrusts the spindles sequentially in an axial direction so as to raise their upper ends above the level of turret 60. In the illustrated embodiment (FIG. 5), a cam 65 in the form of a truncated cone has a stub 66 extending through a support plate 67 which is carried by the gear box 43. A snap ring 68 holds the stub shaft in place. The center of turret 60 is offset to the right of the center of platen table 26, as viewed in FIG. 2, so that a raised spindle of turret 60 is substantially in linear alignment with the anvil 13 and the center of platen table 26.

The printing disc 15 has a central opening 70 matching in shape and size the upper end of a spindle on which it should be used. In this manner, turret 60 seats upon the upper end of a spindle for rotation therewith about the vertical axis of the spindle. The circumferential edge of printing disc 15 is slotted as at 71 to insure a proper position for printing by engaging a slot with a pivotal lever 72, (FIG. 1) which definesa location station. There are two concentric, closed arcuate paths of characters on the face of disc 15. One path of characters 73 is for visual orientation, and it is this row that is associated with the slots 71 and lever 72. A second path 74 on the underside of disc 15 comprises the raised characters of the disc which are actually inserted between the anvil l3 and piston 24 for a printing operation. When a visible character of path 73 is aligned with lever 72, a corresponding raised character from path 74 is then in printing position between the anvil l3 and piston 24.

In the preferred embodiment, the printing disc 15 is formed from a deformable, resilient, synthetic polymeric resin of predetermined elastic limits. Various resins, principally thermoplastic resins, may be used for this purpose, such as the polyvinyl resins like polyvinyl acetate, polyvinyl butyral, polyvinyl chloride, polyvinylidene chloride, and mixtures thereof, polyacrylic acid, polymethacrylic acid, polyacrylic esters, and polymethacrylic esters. The use of known plasticizers and modifiers can be incorporated in the resins to impart the physical properties desired, such as the deformability and predetermined range of elastic limits. Additionally, the present printing disc is made with the smaller letters, such as an i" or a period of reduced height as compared with the height of larger letters such as a capital W or M.

The raised characters of a printing disc of this invention can be produced by casting, embossing, grinding, or the like in order to convert them to such different heights. A recommended technique is to use a photopolymer to produce the printing disc by light exposure and etching. One such photopolymer that also has the desired deformability and elastic limits is sold by Du- Pont under the trademark Dycril." In this aspect of the invention, for example, a disc of the photosensitive photopolymer resinous material is prepared comprising about a 0.040 inch layer of the photopolymer on a 0.060 inch aluminum base. The disc is exposed to ultraviolet light through an Addressograph-Multigraph VariTyper typemaster with the font desired as an image-producing medium. After the disc has been etched, as by an alkaline wash, to remove material around all of the resulting raised characters, the latter are of uniform height, for example, about 0.040 inch in relief. Slots 71 are formed as by milling, followed by coding of the center hole of the disc for use with a proper spindle.

If the master disc were to be run in this condition, there would be an overwhelming force applied to the smaller characters, such as an i, and this would cut and destroy the transfer and printable papers. In the present case, the smaller raised characters are first reduced in height. For instance, the printing disc may first be used in a direct image printing machine in a dry" run. The resulting compressive force does exceed the elastic limit of the resinjn the smaller of the raised characters and therefore reduces their height to a height that is less than that of the height of the larger characters. The smaller raised characters thereby receive a permanent set.

When such a disc is not placed in actual operation, as explained more fully hereinafter, the height of a selected platen causes a certain space between the face of a selected character, such as a W'," and the anvil. That space is used to compress a complete release ribbon and a tape of paper stock upon which the printing is to take place. A large W or M" is able to withstand the pressure applied and to cause a uniform release of a large area of the ribbon. Subsequently, when a small i or other small character is placed in a printing position, the character does not approach as close to the anvil because of its previous height reduction by compression above its resinous elastic limits. In this way, a carrier strip or ribbon is not perforated by relatively small characters because of their relative tiny size, even though relatively great pressure is applied during a printing operation.

Strips of transfer paper 75 and printable paper 76 (FIG. 2) are advanced in unison from their respective rolls in superposed relation between the anvil 13 and platen table 26 of the piston and intermittently halted for the printing of each selected raise character from disc 15. The printable paper or stock 76 upon which printing takes place is preferably a highly nonporous paper or an acetate film in order that a complete re lease of the ribbon material uniformly sets on the surface in a dense transfer. The means for periodically advancing and/or spacing the transfer and printable papers do not form a part of the present invention and therefore are not described in detail. Such means can include any of those means known in the art for this purpose. Illustrative means are schematically illustrated in FIG. 2. For example, advance of the papers can be operated as from cam wheel 47 on shaft 46. Or a rack 77 may be advanced to turn a shaft 78 by engagement with a gear 79, the shaft through cooperating gears 81 and 82 turning a drive roller 83 having a companion, cooperating roller 84. Spacing can also be accomplished by using the feeler lever 72 to engage slots 71 in printing disc 15 of variable radial length as disclosed, for example, in U.S. Pat. No. 2,742,830 to Wirtz.

Operation The present printing machine embodies a transfer pressure control, which varies the amount of interference between the closing anvil and piston, to maintain the stress on a raised character being printed below a predetermined maximum. By interference is meant the distance between the anvil l3 and platen table 26 (exclusive of the platen strips) at the top of the constant piston stroke, minus the sandwich comprising the printing disc 15, transfer paper 75, and printable paper 76. The several differing platen strips 32 through 36 therefore effect the difference in transfer pressure and establish many different pressures. These differing pressures assure a complete transfer of the image for a range of printing discs of differently sized or shaped characters, and at the same time preclude overstressing and damaging of the characters. The amount of interference is changed by turning the two positively and sequentially driven turret 60 and platen table 26, so that platen strips of differing thicknesses can vary the effective imaging pressure as desired. Further, only that printing disc of raised characters of proper height and- /or printing area can be mounted in an operable position in the printing machine.

The several printing disc font members 15 each has i a fundamental interference characteristic in that there is a selected character height for the largest area characters. Each disc will have such fundamental height related to its own characteristics, and it will differ from other discs which will require more or less pressure for print release. As to each individual disc, slight variances in character height will also be provided to accommodate the variations in intra-font character area, for example the period and other small area characters will be of lesser height than the large area upper case W.

Therefore, the term fundamental interference characteristic" will be used hereafter and in the claims to carry this definition.

More particularly, turret 60 is rotated about shaft 61 until a selected spindle has struck cam 65 and therebyi can have known indexing means which momentarily locks either or both discs in position when a selected I station is reached. A printing disc is next placed over the raised exposed end of the spindle raised by cam 65 with the raised characters of the disc face down. Only those printing discs having raised characters which can be safely used with the selected platen strip have the proper central opening, such as opening (FIG. 1), to accommodate the shape and size of the exposed end of the raised spindle and can therefore be mounted in an operable position in the machine. Other printing discs will be rejected.

The machine is now ready for use. The transfer paper and printable paper 76 are periodically moved in unison between the anvil 13 and piston 24 and positioned before each print. The printing disc 15 is rotated with its selected, support spindle until a selected, desired character is reached by inserting the pivoted lever 72 in a slot 71 designating the desired character. Each printing operation is actuated by operation of clutch mechanism 50 in a known manner which actuates the toggle assembly. There results a relatively slow, even application of pressure by the piston 24, unlike the hammer application as a typewriter, to compress together the papers and printing disc. Whether the character to be printed has a relatively large height and/or printing area like the W of FIG. 6, or a relatively small height and/or printing area like the period of FIG. 7, the flat platen strip provides a sharp, even print of the character onto paper 76 and does so for a long useful life of the printing disc. The image area and height of a character are therefore correlated to conditions of the printing operation, so that at no time is a stress on the character reached which is of sufficient magnitude to chip or smash the character or otherwise shorten its useful life.

Although the invention has been described in connection with a composing machine, it is understood that the invention may be used in still other types of printing machines. While the foregoing describes one presently preferred embodiment, the invention may be practiced in still other forms within the scope of the following claims.

What is claimed is:

1. Printing apparatus for imprinting on sheet material character-by-character using a selected one of a plurality of printing font members, each having its own series of print characters with printing face characteristics requiring a fundamental interference characteristic correlated with the character print loading range required to effect acceptable printing by the font, said fundamental interference characteristic being generally uniform to all characters of the font and differing from font to font comprising:

a. a printing press having first and second members relatively closeable towards one another to apply print pressure when the font member and print receiving sheet material are between the anvils;

b. a first carrier having a series of insert blocks of different heights each having its height correlated with the fundamental interference characteristic of at least one printing font member to be used with the apparatus, and capable of reducing the space between the members to the distance which will generate the required character print loading when used with a correlated printing font member, said carrier being selectively positionable to place different ones of said blocks between the anvils; c. a second carrier having means to receive and support individual printing font members in a plurality of unique locations, each location being capable of receiving only font members having a given fundamental interference characteristic, said carrier being movable to establish the font member in an active position where the font member can coact selectively with the members; and means interconnecting the carriers for coordinated movement such that placement of the second carrier into active position for the carried font will cause movement of said first carrier to place the block having a height correlated with the fundamental interference characteristic of said carried font member, between said members to coact with the characters on the font member during printing. 2. A printing apparatus for imprinting on sheet material at aprinting station with a selected one of a plurality of printing members;

a. each printing member having a font of characters which is useful to press letters one at a time against a superposed supply web coated with a pressure release printing material and a web of acceptance material to be imprinted, the supply and acceptance webs have a determinable and known ideal printing pressure per unit area, each printing member font having characters of total unit areas unique to that font, the elevation of the characters of a given font from a reference plane including the main body of said font being such that smaller area characters extend a lesser distance from the plane than the larger area characters;

b. a printing press having first and second members closeable toward one another to apply print pressure, said press closeable from an open condition to a maximum closed condition with at least enough force to produce full release print pressure upon the largest printing member character;

c. a carrier having a series of insert blocks of varying heights correlated with said printing members to reduce the space between said members in said closed condition to that distance which will result in a total pressure upon the characters of the font to produce said ideal pressure of the webs, said carrier being repositionable to place a block related to another printing member into said press upon a change of printing members;

d. a carrier for said printing members, said carrier having means for accepting said printing members in a plurality of support positions, each support position accepting only printing members that are to be used with a given one of said insert blocks and e. means for moving said carrier of the printing member to place the font thereof into position between said members and to simultaneously move said carrier for said blocks to place the proper insert block between said members.

3. A printing apparatus for imprinting on sheet material at a printing station with a selected one of a plurality of printing font members each with a fundamental interference characteristic producing a font of characters of a plurality of heights depending upon their surface area, said apparatus comprising movable printing member support means for supporting the printing members, said movable printing member support means having a plurality of mounting positions, each mounting position of which has a mounting means unique to a given fundamental interference characteristic, a plurality of spacer blocks of different heights each of which is related to one of the fundamental interference characteristics, means for moving said printing member support means to select one of said plurality of mounting means corresponding to a selected font of characters, and position it to support said selected font, means for moving said spacer blocks so as to position at the printing station the spacer block associated with a selected said font of characters in response to movement of said printing member support means to select the mounting means associated with said selected font of characters.

4. A printing apparatus as set forth in claim 3 wherein each of said mounting members has an extended position for mounting an associated said printing font member and a normal retracted position, and means for selectively displacing one of said mounting members from its retracted position to its extended position.

5. A printing apparatus as set forth in claim 4 wherein each of said mounting members is a spindle having one end configured for mounting only an associated one of said printing members when said spindle is in its extended position.

6. A printing apparatus as set forth in claim 5 wherein said printing member support means is a rotatable turret means for carrying said spindles and said spindles are spaced apart in a circular array about the axis of rotation of said turret means, and said displacing means includes stationary cam means positioned relative to said turret means for sequentially displacing each of said spindles to its extended position as said turret means is rotated about said axis of rotation.

7. A printing apparatus as set forth in claim 6 wherein said means for moving said spacer member includes means interconnecting said rotatable turret table means with said spacer members for displacing said spacer members in accordance with rotational movement of said turret means.

8. A printing apparatus as set forth in claim 1 wherein said first carrier includes a rotatably mounted support table, said block members being carried by said table and spaced apart in a circular array about the axis of rotation of said table, said second carrier including a rotatably mounted printing font member support table rotatably movable to each of said plurality of positions.

9. A printing apparatus as set forth in claim 8 wherein said insert blocks are spaced apart on said spacer support table at locations corresponding to said unique locations of said printing member support table.

10. A printing machine for printing with a selected one of a plurality of printing members each having a different font of raised printing characters thereon comprising: a relatively stationary anvil means, piston means movable for relative linear movement toward and away from said anvil means, printing member mounting means including a first support member movable to selected positions, a plurality of spaced apart mounting members carried by said first support member, said mounting members each being shaped to remeans for relative movement therebetween for positioning a selected one of said block members to said printing position between said anvil means and said piston means, and means interconnecting said first and second movable support members so that movement imparted to said first support member to position the printing member carried thereby to said printing position also imparts movement to said second support member to position an associated one of said block members to said printing position between said piston means and said anvil means. 

1. Printing apparatus for imprinting on sheet material character-by-character using a selected one of a plurality of printing font members, each having its own series of print characters with printing face characteristics requiring a fundamental interference characteristic correlated with the character print loading range required to effect acceptable printing by the font, said fundamental interference characteristic being generally uniform to all characters of the font and differing from font to font comprising: a. a printing press having first and second members relatively closeable towards one another to apply print pressure when the font member and print receiving sheet material are between the anvils; b. a first carrier having a series of insert blocks of different heights each having its height correlated with the fundamental interference characteristic of at least one printing font member to be used with the apparatus, and capable of reducing the space between the members to the distance which will generate the required character print loading when used with a correlated printing font member, said carrier being selectively positionable to place different ones of said blocks between the anvils; c. a second carrier having means to receive and support individual printing font members in a plurality of unique locations, each location being capable of receiving only font members having a given fundamental interference characteristic, said carrier being movable to establish the font member in an active position where the font member can coact selectively with the members; d. and means interconnecting the carriers for coordinated movement such that placement of the second carrier into active position for the carried font will cause movement of said first carrier to place the block having a height correlated with the fundamental interference characteristic of said carried font member, between said members to coact with the characters on the font member during printing.
 2. A printing apparatus for imprinting on sheet material at a printing station with a selected one of a plurality of printing members; a. each printing member having a font of characters which is useful to press letters one at a time against a superposed supply web coated with a pressure release printing material and a web of acceptance material to be imprinted, the supply and acceptance webs have a determinable and known ideal printing pressure per unit area, each printing member font having characters of total unit areas unique to that font, the elevation of the characters of a given font from a reference plane including the main body of said font being such that smaller area characters extend a lesser distance from the plane than the larger area characters; b. a printing press having first and second members closeable toward one another to apply print pressure, said press closeable from an open condition to a maximum closed condition with at least enough force to produce full release print pressure upon tHe largest printing member character; c. a carrier having a series of insert blocks of varying heights correlated with said printing members to reduce the space between said members in said closed condition to that distance which will result in a total pressure upon the characters of the font to produce said ideal pressure of the webs, said carrier being repositionable to place a block related to another printing member into said press upon a change of printing members; d. a carrier for said printing members, said carrier having means for accepting said printing members in a plurality of support positions, each support position accepting only printing members that are to be used with a given one of said insert blocks and e. means for moving said carrier of the printing member to place the font thereof into position between said members and to simultaneously move said carrier for said blocks to place the proper insert block between said members.
 3. A printing apparatus for imprinting on sheet material at a printing station with a selected one of a plurality of printing font members each with a fundamental interference characteristic producing a font of characters of a plurality of heights depending upon their surface area, said apparatus comprising movable printing member support means for supporting the printing members, said movable printing member support means having a plurality of mounting positions, each mounting position of which has a mounting means unique to a given fundamental interference characteristic, a plurality of spacer blocks of different heights each of which is related to one of the fundamental interference characteristics, means for moving said printing member support means to select one of said plurality of mounting means corresponding to a selected font of characters, and position it to support said selected font, means for moving said spacer blocks so as to position at the printing station the spacer block associated with a selected said font of characters in response to movement of said printing member support means to select the mounting means associated with said selected font of characters.
 4. A printing apparatus as set forth in claim 3 wherein each of said mounting members has an extended position for mounting an associated said printing font member and a normal retracted position, and means for selectively displacing one of said mounting members from its retracted position to its extended position.
 5. A printing apparatus as set forth in claim 4 wherein each of said mounting members is a spindle having one end configured for mounting only an associated one of said printing members when said spindle is in its extended position.
 6. A printing apparatus as set forth in claim 5 wherein said printing member support means is a rotatable turret means for carrying said spindles and said spindles are spaced apart in a circular array about the axis of rotation of said turret means, and said displacing means includes stationary cam means positioned relative to said turret means for sequentially displacing each of said spindles to its extended position as said turret means is rotated about said axis of rotation.
 7. A printing apparatus as set forth in claim 6 wherein said means for moving said spacer member includes means interconnecting said rotatable turret table means with said spacer members for displacing said spacer members in accordance with rotational movement of said turret means.
 8. A printing apparatus as set forth in claim 1 wherein said first carrier includes a rotatably mounted support table, said block members being carried by said table and spaced apart in a circular array about the axis of rotation of said table, said second carrier including a rotatably mounted printing font member support table rotatably movable to each of said plurality of positions.
 9. A printing apparatus as set forth in claim 8 wherein said insert blocks are spaced apart on said spacer support table at locations corresponding to said unique locations of said printing member support table.
 10. A printing machine for printing with a selected one of a plurality of printing members each having a different font of raised printing characters thereon comprising: a relatively stationary anvil means, piston means movable for relative linear movement toward and away from said anvil means, printing member mounting means including a first support member movable to selected positions, a plurality of spaced apart mounting members carried by said first support member, said mounting members each being shaped to receive only selected printing members having characters of substantially equal area. said first support member, when positioned to one of said selected positions, presenting a raised printing character on the printing member carried carried by the selected mounting member in a printing position between said anvil means and said piston means, spacer means including a second movable support member and a plurality of spaced apart block members of different thicknesses carried by said second support member and respectively associated with one of said printing members, means for movably mounting said second support member to said piston means for relative movement therebetween for positioning a selected one of said block members to said printing position between said anvil means and said piston means, and means interconnecting said first and second movable support members so that movement imparted to said first support member to position the printing member carried thereby to said printing position also imparts movement to said second support member to position an associated one of said block members to said printing position between said piston means and said anvil means. 